ENVI_VEG_INDEX_AVAILABLE_INDICES

This function returns the number of vegetation indices that can be calculated on an input data file. It can optionally return the names of these indices, a classification describing the purpose of the index, or, if no indices are available, a descriptive error specifying the reason why.

Syntax

Arguments

FID

Use this keyword to specify the file ID for the input file.

Keywords

ERROR_STRING (optional)

Set this keyword to a named variable in which to return a descriptive error string describing the reason that no vegetation indices are available, if the return value of the function is 0. Otherwise, this keyword is undefined.

VI_LIST (optional)

Set this keyword to a named variable in which to return an array of long integers containing the numeric indices associated with each vegetation index available for calculation, if any. These indices can be used to specify the desired subset of indices for the ENVI_VEG_INDEX_DOIT procedure to calculate. If the ENVI_VEG_INDEX_AVAILABLE_INDICES return value is 0, this keyword is undefined.

VI_NAMES (optional)

Set this keyword to a named variable in which to return a string array containing the names of all vegetation indices available for calculation, if any. If the ENVI_VEG_INDEX_AVAILABLE_INDICES return value is 0, this keyword is undefined.

VI_TYPE (optional)

Set this keyword to a named variable in which to return a string containing the names of the categories for all vegetation indices available for calculation. If the ENVI_VEG_INDEX_AVAILABLE_INDICES return value is 0, this keyword is undefined.